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C - Write and Erase

Score : $300$ points

Problem Statement

You are playing the following game with Joisino.

• Initially, you have a blank sheet of paper.
• Joisino announces a number. If that number is written on the sheet, erase the number from the sheet; if not, write the number on the sheet. This process is repeated $N$ times.
• Then, you are asked a question: How many numbers are written on the sheet now?

The numbers announced by Joisino are given as $A_1, ... ,A_N$ in the order she announces them. How many numbers will be written on the sheet at the end of the game?

Constraints

• $1≤N≤100000$
• $1≤A_i≤1000000000(=10^9)$
• All input values are integers.

Input

Input is given from Standard Input in the following format:

$N$

$A_1$

$:$

$A_N$

Output

Print how many numbers will be written on the sheet at the end of the game.

3
6
2
6

1

The game proceeds as follows:

• $6$ is not written on the sheet, so write $6$.

• $2$ is not written on the sheet, so write $2$.

• $6$ is written on the sheet, so erase $6$.

Thus, the sheet contains only $2$ in the end. The answer is $1$.

4
2
5
5
2

0

It is possible that no number is written on the sheet in the end.

6
12
22
16
22
18
12

2